Fluid pressure operated disk brake for aircraft



Sept. 27, 1949. w. H. DU BOIS ETAL 2,433,362

FLUID PRESSURE OPERATED DISK BRAKE FOR AIRCRAFT 2 Sheets-Sheet 1 FiledJan. 20, 1945 INVENTOR.

Sept. 27, 1949. w. H. DU BOIS EI'AL FLUID PRESSURE OPERATED DISK BRAKEFOR AIRCRAFT Filed Jan. 20, 1945 2 Sheets-Sheet 2 Patented Sept. 27,1949 FLUID PRESSURE OPERATED DISK BRAKE FOB AIRCRAFT William H. Du Botsand Irving F. Chapin, South Bend, Ind., assignors to Bendix AviationCorporation, South Bend, Ind a corporation of Delaware Continuation ofapplication Serial No. 573,716, January 20, 1945. This applicationSeptember 14, 1946, Serial Rim-697.022

15 Claims. (Cl. 188-152) This invention relates to brakes which are soconstructed and arranged as to be particularly adapted for use withaircraft landing gear. The present application is a continuation of ourapplication serial No. 573,716, filed January 20, 1945, now abandoned.

Since it is customary to retract the landing gear of airplanes into thewings, planes having unusually thin wing sections pose a particularlydifilcult problem in the design of landing gear.

This applied especially to the brake arrangement,

since diminution of the landing gear width decreases the space availablefor the brake.

An object of the present invention i to provide a brake constructionwhich can be satisfactorily used with a landing gear wherein the lowerend of the strut and the wheel are positioned exceptionally close to oneanothen'the brake being located on the inboard side of the wheel.

A more specific object of the present invention is to provide an inboarddisk brake having an actuator so arranged and constructed as to permitthe wheel to be located in close proximity to the lower end of thestrut.

A further object of the present invention is to obtain a cooling now ofair over the friction disks of a disk brake.

Other objects and advantages of the present invention will becomeapparent during the following description. In the accompanying draw=ings:

Figure 1 is an end view of a brake as applied to an aircraft landinggear, a portion of the brake being cut away to show the brake actuat-=ing means in section;

Figure 2 is a cross section taken on the line 2-2 of Figure 1, exceptthat the strut, axle, and wheel are shown in outline; and

Figures 3 and 4 are-sections taken on the lines 3-3 and 6-5 respectivelyof Figure 1.

In the illustrated landing gear, a cantilever axle i2 is supported atthe lower end of strut it. Mounted on bearings 56 for rotation aboutaxle i2 is a wheel ll; having an overhanging rim portion 25 beneathwhich is a brake cavity 22. Secured to the wheel within the overhangingrim portion 26 are a plurality of driving keys 24$ which extend axiallythrough peripheral slots in the rotating disks 26, 2t and 38 to drivethe same. The number of rotating disk may be varied according to therequirements of the particular brake installation. The rotating diSksIG,28 and 30 are movable axially along the driving keys 2t,

thus enabling them to be forced into contact with as 2 the cooperatingnon-rotating disk members of the brake structure.

The non-rotating disk members of the brake are supported on a fixedmember 32, said fixed member 32 being secured to a flange 34 on thelower end of strut l4. The member 32 has a plurality of axiallyextending spokes 36 formed integra'l therewith, against the outer endsof which a non-rotatable and axially fixed disk 38 is held by means of aplurality of through bolts til.

Sleeves 42 are mounted on the bolts to and serve as anchors for threeaxially movable but nonrotatable disks 44, a6 and 48. Both sides ofdisks t6 and as are lined with friction material 50, as well as the leftface of disk 38 and the right face of disk 44 (referring to Figure 2 or4).

The actuating means for exerting compressive force on the brake diskscomprises a plunger or piston member 52 which is movable axially withina chamber 54 provided in a fixed housing 5%, which, in the illustratedembodiment of the invention, is formed integral with the-brakesupporting member 32. It will be noted that, owing to the relativelysmall space available for the brake structure between the strut it andthe wheel M, the rotating and non-rotating friction disks fillsubstantially the entire brake cavity. The housing es in which ismounted the brake actuating plunger member 52 is therefore mounted inthe vertical plane of the strut it and is discontinued at 58 and 60 toprovide an opening through which the strut extends.

The chamber and plunger member 52 therefore are c-shaped, Or in otherwords, they have the form of an annulus except for the space left openat the top of the assembly. At both ends of this incomplete annulus, thechamber 5st and the plunger 52 are provided with enlarged cylindricalend portions, one of which is generally indicated at 52 in the sectionedpart of Figure l. The enlarged cylindrical portions at opposite ends ofthe chamber 54 serve the important function oi positively locating thesealing member 5 5 which rests against the face 66 of plunger 52 toprevent the escape of liquid past the sides of said plunger, liquidbeing admitted to the space 58 in chamber 5a through either one of twoinlets it (two inlets preferably being provided so that identical brakescan be used on either the left or right wheel of the plane). The sealingmember 64, which is shown in cross-section inv Figures 2, Sand 4, has aninner lip 72, an outer lip 74, and a circular'lip 78 in each cylindricalend portion 62, the lips 16 joining the inner lip '82 to the outer lipit to form, in eflect, a single tively located by means of the enlargedend portions, this possibility is avoided, and satisfactory sealing isinsured.

A bleed passage 18 may be located at each end or high point of thechamber 54, the usual bleeder' fitting 80 being arranged normally toplug the bleed opening.

A plurality of circumferentially spaced return springs 82 are located inchambers 84 formed in member 32, and are arranged to act through collars86 and rods 88 to return disk 44 and plunger 52 to released positionafter each brake application.

In operation, when the brakes are to be applied, fluid under pressure isforced through whichever inlet is connected to the brake line, and intothe space 68 at the front of c-shaped chamber 58. The fluid acts againstsealing member 64 and the C-shaped plunger 52 to exert an axial pressuretending to move the several disks of the brake into frictional contactwith one another, and thereby retard rotation of the wheel IS.

A tremendous amount of heat is generated during the application ofbrakes on an airplane. For this reason, it is desirable to provide meansfor cooling the brake disks, particularly those disks which are notlined with friction material, in this case the rotating disks 28, 28 and30. We are able to obtain an appreciable cooling effect on said rotatingdisks by discontinuing the lining material on the non-rotating disks atthe place where the strut i4 passes between the ends of the brakeactuator, or in other words between points 58 and 60. The disks 28, 28and 30, as they pass through this open space (shown at the top of Figure2) come into cooling contact with air which is flowing past the wheel,thus dissipating some of the heat which results from the brakeapplication. This arrangement is patricularly suitable in the presentcase because of the fact that the brake applying pressure of the fluidis not available to act directly on that part of the brake h'ing betweenthe ends of the O-shaped acuator, and pressure in this interspace istherefore comparatively low. If the non-rotating disks were lined atthis point, the lining would tend to wear unevenly because of the lackof uniform pressure around the entire disk.

Although a particular embodiment of our invention has been described, itwill be understood by those skilled in the art that the object of theinvention may be attained by the use of constructions diiferent incertain respects from that disclosed without departing from theunderlying principles of the invention. We therefore desire by thefollowing claims to include within the scope of our invention all suchvariations and modifications by which substantially the results of ourinvention may be obtained through the use of substantially the same orequivalent means.

We claim:

1. In an aircraft landing gear including a substantially upright strut,a horizontally extending axle supported at the lower end of said strut,and a wheel mounted on said axle at one side of the strut, a brakemounted on the inboard side of the wheel comprising a plurality ofdisks, one or more of which rotate with the wheel, and one or more 4 ofwhich are non-rotatable, the non-rotatable disks being lined withfriction material, an axially movable pressure transmitting memberarranged to act against said disks, a fixed housing member providing achamber in which said pressure transmitting member reciprocates, thechamber having an opening to receive fluid under pressure to act againstthe pressure transmitting member, said fixed housing member beinglocated at least partially in the vertical plane of the lower end of thestrut, said pressure transmitting mem ber and the chamber in which itreciprocates having the form of an incomplete annulus provided with anenlarged cylindrical portion at each end, the ends of said incompleteannulus being spaced apart to straddle the strut, a sealing memberlocated in the chamber against the face of the pressure transmittingmember to prevent the escape of fluid past said member, said sealingmember being shaped to conform to the chamber and being retained againstcircumferential movement by the fit of itsv enlarged end portions in theenlarged ends of the chamber, said seal having a continuous lipextending along the outer wall of the chamber, around the wall of eachenlarged end portion, and along the inner wall of the chamber, thefriction material lining being absent from the portion of the otherwiselined disks located between the ends of the pressure transmittingmember, thereby permitting a cooling flow of air over the surfaces ofthe rotating disks at this point.

' 2. In an aircraft landing gear including a substantially uprightstrut, a horizontally extending axle supported at the lower end of saidstrut, and a wheel mounted on said axle at one side of the strut, abrake mounted on the inboard side of the wheel comprising a plurality ofdisks, one or more of which rotate with the wheel, and one or more ofwhich are non-rotatable, an axially movable pressure transmitting memberarranged to act against said disks, a fixed housing member providing achamber in which said pressure transmitting member reciprocates, saidfixed housing member being located at least partially in the verticalplane of the lower end of the strut, said pressure transmitting memberand the chamber in which it reciprocates having the form of anincomplete annulus provided with an enlarged cylindrical portion at eachend, the strut through the space between the ends of said incompleteannulus, a sealing member located in the chamber against the face of thepressure transmitting member to prevent the escape of fluid past saidmember, said sealing member being shaped to conform to the chamber andbeing retained against circumferential movement by the fit of itsenlarged end portions in the enlarged ends of the chamber, said sealhaving a continuous lip extending along the outer wall of the chamber,around the wall of the respective enlarged end portion, and along theinner wall of the chamber.

3. In an aircraft landing gear including a substantially upright strut,a horizontally extendin'g axle supported at the lower end of said strut,and a wheel mounted on said axle at one side of the strut, a brakemounted on the inboard side of the wheel comprising a. plurality ordisks, one or more of which rotate with the wheel, and one ormore ofwhich are non-rotatable, an axially movable pressure transmitting memberarranged to act against said disks, a fixed housing member providing achamber in which said pressure transmitting member reciprocates, saidfixed housing aceasea member being located at least partially in thevertical plane of the. lower end of the strut, said pressuretransmitting member and the chamber in which it reciprocates having theform of an incomplete annulus provided with an enlarged cylindricalportion at each end, the strut passing through the space between theends of said incomplete annulus, a sealing member located in the chamberagainst the face of the pressure the wheel comprising a plurality ofdisks, one or more of which rotate withthe wheel, and one or more ofwhich are non-rotatable, an axially movable pressure transmitting memberarranged to act against said disks, and a fixed housing member providinga chamber in which said pressure transmitting member reciprocates, saidfixed housing member being located at least partially in the verticalplane of the lower end of the strut, said pressure transmitting memberand the chamber in which it reciprocates having the form of anincomplete annulus provided with an enlarged cylindrical portion at eachend, the ends of said incomplete annulus being spaced apart to straddlethe strut.

5. In an aircraft landing gear including a sub stantially upright strut,a horizontally extending axle supported at the lower end of said strut,a wheel mounted on said axle at one side of the strut, and a disk brakemounted on the inboard side of the wheel, actuating means for said brakecomprising an axially movable pressure transmitting member, and a fixedhousing member located at least partially in the vertical plane of thelower end of the strut and providing a chamber in which said pressuretransmitting member reciprocates, said pressure transmitting member andthe chamber in which it reciprocates having the form of an incompleteannulus, between the ends of which the strut passes.

6. In an aircraft landing gear including a sub- I stantlally uprightstrut, a horizontally extending axle supported at the lower end of saidstrut, and

a wheel mounted on said axle at one side of the strut, a brake mountedon the inboard side of the wheel comprising a plurality of disks, one ormore of which rotate with the wheel, and one or more of which arenon-rotatable, either the rotating or non-rotating disks being linedwith friction material, and actuating means for said brake arranged toexert pressure in an axial direction to move said disks into contactwith one another,

said actuating means comprising a cylinder and piston combination whichis located at least partially in the vertical plane of the lower end ofthe strut, and which has the form of an incomplete annulus left open atthe top to provide space for the strut, the lining being absent from theotherwise lined disks at this point to permit a cooling flow of air overthe surfaces of the disks.

'7. In an aircraft landing gear including a substantially upright strut,a horizontally extending axle supported at the lower end of said strut,and a wheel mounted on said axle at one side of the strut, a brakemounted on the inboard side of the wheel comprising a plurality ofdisks, one or more of which rotate with the wheel, and one or more ofwhich are non-rotatable, and actuating means for said brake arranged toexert pressure in an axial direction to move said disks into contactwith one another, said actuating means comprising a cylinder and pistoncombination which is located at least partially in the vertical plane ofthe lower end of the strut, and which has the form of an incompleteannulus left open at the top to provide space'for the strut.

8. In an aircraft landing gear including a strut, a horizontallyextending axle supported at the lower end of saidstrut, a wheel mountedon said axle at one side of the strut, and a disk brake mounted on theinboard side of the wheel, actuating means for said brake located atleast partially in the vertical plane of the lower end of the strut andhaving the form of an incomplete annulus left open at one side toprovide space for said strut.

9. A brake comprising a plurality of disks, one or more of which arecapable of rotating, and one or more of which are non-rotatable, thenon-rotatable disks being lined with friction material, an axiallymovable pressure transmitting member arranged to act against said disks,a fixed housing member providing a chamber in which said pressuretransmitting member reciprocates, the chamber having an opening toreceive fluid under pressure to act against the pressure transmittingmember, said pressure transmitting member and the chamber in which itreciprocates, having the form of an incomplete annulus provided with anenlarged cylindrical portion at each end, a sealing member located inthe chamber against the face of the pressure transmitting member toprevent the escape of fluid past said member, said sealing member beingshaped to conform to the chamber and being retained againstcircumferential movement by the fit of its enlarged end portion in theenlarged ends of the chamber, said seal having a continuous lipextending along the outer wall of the chamber, around the wall of eachenlarged end portion, and along the inner wall of the chamber, thefriction material lining being absent from the-portion of the otherwiselined disks located between the ends of the pressure transmittingmember, thereby permitting a cooling flow of air over the surfaces ofthe rotating disks at this point.

10. A brake comprising a plurality of disks, one or more of which arecapable of rotating, and one or more of which are non-rotatable, anaxially movable pressure transmitting member arranged to act againstsaid disks, a fixed housing member providing a chamber in which saidpressure transmitting member reciprocates, said pressure transmittingmember and the chamber in which it reciprocates having the form of anincomplete annulus provided with an enlarged cylindrical portion at eachend, a sealing member located in the chamber against the face of thepressure transmitting member to prevent the escape of fluid past saidmember, said sealing member being shaped to conform to the chamber andbeing retained against circumferential movement by the fit of itsenlarged end portions in the enlarged ends of the chamber. said sealhaving a continuous lip extending along the outer wall of the chamber,around the wall of each enlarged end portion, and along the inner wallof the chamber. 1

11. A brake comprising a plurality of disks, one

or more of which are capable of rotating, and one or more of which arenon-rotatable, an axially movable pressure transmitting member arrangedto act against said disks, a fixed housing member providing a chamber inwhich said pressure transmitting member reciprocates, said pressuretransmitting member and the chamber in which it reciprocates having theform of an incomplete annulus provided with an enlarged cylindricalportion at each end, a sealing member located in the chamber against theface oi the pressure transmitting member to prevent the escape of fluidpast said member, said sealing member being shaped to conform to thechamber and being retained against circumferential movement by the fitof its enlarged end portions in the enlarged ends of the chamber.

12. A brake comprising a plurality of disks, one or more of which arecapable of rotating, and one or more of which are non-rotatable, anaxially movable pressure transmitting member arranged to act againstsaid disks and having the form of an incomplete annulus provided with anenlarged cylindrical portion at each end, and a fixed housing memberproviding a chamber in which said pressure transmitting memberreciprocates, said chamber also having the form of an incomplete annulusprovided with an enlarged cylindrical portion at each end.

13. A brake comprising a plurality of disks, one or more of which arecapable of rotating, and one or more of which are non-rotatable, anaxially movable pressure transmitting member arranged to act againstsaid disks and having the form on an incomplete annulus, and a fixedhousing member providing a chamber in which said pressure transmittingmember reciprocates, said chamber also having the form or an incompleteannulus.

14. A brake comprising a plurality of disks, one or more of which arecapable oi rotating, and one or more or which are non-rotatable, eitherthe rotating or non-rotating disks being lined with friction material,and actuating means arranged to exert pressure in an axial direction tomove said disks into contact with one another, said actuating meanscomprising a cylinder and piston combination which has the form of anincomplete annulus left open at one side, the lining being absent fromthe otherwise lined disks at this point to permit a COOllngflOW of airover the surfaces of the disks.

15. A brake comprising a lurality of disks, one or more of which arecapable of rotating, and one or more oi. which are non-rotatable, andactuating means, arranged to exert pressure in an axial direction tomove said disks into contact with one another, constituted by a cylinderand piston combination which has the form of an incomplete annulus leftopen at one side.

WILLIAM H. DU BOIS. IRVING F. CHAPIN.

REFERENCES CITED The following references are of record in the file ofthis patent;

UNITED STATES PA'I'EN'IS Number Name Date 534,977 Sperry Feb. 26, 18952,017,715 Goodyear et al Oct. 15, 1935 2,068,956 La Brie Jan. 26, 19372,376,828 Sneed May 22, 1945 2,423,011 Du Bois June 24, 1947 FOREIGNPATENTS Number Country Date 310,320 Italy Aug. 9, 1933

